Anxiety disorders are among the most common psychiatric illnesses in children and adolescents with prevalence rates averaging 5-10%. These disorders are associated with significant short- and long-term impairment in academic, familial, social, and psychological functioning. Although medication and cognitive-behavioral therapies have been found to be effective treatments, efforts to prevent anxiety disorders in youth have been limited. In light of the high prevalence, the associated impairment, and the cost of treating these disorders (estimated at 42 billion dollars a year for adults), preventive measures could have a significant public health impact. Family aggregate studies indicate that children of anxious parents are at an elevated risk for developing anxiety disorders and thus an important target population for prevention. Results from the PI's K23 pilot study found that a brief family-based intervention reduced the incidence of anxiety disorders in this population by 30-50%. The purpose of this R01 application is to evaluate the efficacy of this intervention for reducing anxiety symptoms and preventing the onset of anxiety disorders in the offspring of anxious parents. In addition, this study will examine theoretically-based mediators of intervention effects. The intervention will be evaluated using a 2 (intervention condition: prevention versus an information- monitoring control) x 4 (assessment period: pre-, post-intervention, 6-, and 12-month follow-up) experimental design. This study uses rigorous scientific methods including a randomized controlled design, multiple informants and measures to assess key constructs, independent evaluators (IEs) to assess outcome and mediator variables, and intensive training for therapists and IEs to assure a high quality of study implementation. This study will be the first aimed at preventing anxiety disorders in the offspring of anxious parents. This application responds to recommendations made by the National Advisory Mental Health Work Group on Mental Disorders Prevention Research (2001) and earlier recommendations from both the Institute of Medicine's Committee on Prevention of Mental Disorders and the NIMH's Prevention Steering Committee (Mrazek & Haggerty, 1994) to develop and evaluate preventive interventions for youth. Anxiety disorders in children and adolescents are common and debilitating illnesses. While cognitive-behavioral treatment is effective, prevention efforts would have a significant public health impact by reducing the need for treatment and altering the life trajectories of at risk children. Offspring of anxious adults are at a significant risk for developing these disorders and an important target for prevention efforts. The purpose of this R01 application is to evaluate whether a short-term psychosocial intervention, developed by the PI in a pilot study, can prevent the onset of anxiety disorders in the offspring of anxious parents.